Role of adhesion forces in mechanosensitive channel gating inStaphylococcus aureusadhering to surfaces
Role of adhesion forces in mechanosensitive channel gating inStaphylococcus aureusadhering to surfaces
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DOI：
10.1038/s41522-020-00141-z
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发表时间：
2020-08-21
影响因子：
9.2
通讯作者：
Busscher, Henk J.
中科院分区：
文献类型：
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作者：
Carniello, Vera;Peterson, Brandon W.;Busscher, Henk J.
细菌膜中的机械敏感通道响应于环境变化而打开或关闭，以允许跨膜转运，包括抗生素摄取和溶质流出。在本文中，我们假设，门控的机械敏感通道是刺激的细菌粘附到表面的力量。因此，通道门控与金黄色葡萄球菌菌株及其同基因Δ mscL突变体的不同表面的粘附力相关，其缺乏MscL（大）通道门控。葡萄球菌由于钙黄绿素的摄取而变得荧光，随着粘附力的增加而增加，并且在亲本菌株中（当粘附力高于4.0 nN时为66%）高于Delta mscL突变体（高于1.2 nN时为40%）。这表明MscL通道在比物理上不同的MscS（小）通道打开并有助于跨膜转运的临界粘附力更高的临界粘附力下打开。通过葡萄球菌杀灭监测抗生素双氢链霉素的摄取。暴露于双氢链霉素的亲本菌株在粘附力高于3.5 nN时产生2.3对数单位的CFU减少，但突变体中的CFU减少仍然很低（1.0对数单位），与粘附力无关。这证实了大通道在比小通道更高的临界粘附力下打开，这也是从钙黄绿素跨膜转运得出的结论。总的来说，这些观察结果支持我们的假设，粘附力的表面发挥了重要作用，旁边的其他既定的驱动力，在葡萄球菌通道门控。这为我们理解感染性葡萄球菌生物膜中的跨膜抗生素摄取和溶质流出提供了一个有趣的扩展，其中细菌经历来自各种表面的粘附力，如其他细菌，组织细胞或植入的生物材料。
Mechanosensitive channels in bacterial membranes open or close in response to environmental changes to allow transmembrane transport, including antibiotic uptake and solute efflux. In this paper, we hypothesize that gating of mechanosensitive channels is stimulated by forces through which bacteria adhere to surfaces. Hereto, channel gating is related with adhesion forces to different surfaces of aStaphylococcus aureusstrain and its isogenic Delta mscLmutant, deficient in MscL (large) channel gating. Staphylococci becoming fluorescent due to uptake of calcein, increased with adhesion force and were higher in the parent strain (66% when adhering with an adhesion force above 4.0 nN) than in the Delta mscLmutant (40% above 1.2 nN). This suggests that MscL channels open at a higher critical adhesion force than at which physically different, MscS (small) channels open and contribute to transmembrane transport. Uptake of the antibiotic dihydrostreptomycin was monitored by staphylococcal killing. The parent strain exposed to dihydrostreptomycin yielded a CFU reduction of 2.3 log-units when adhering with an adhesion force above 3.5 nN, but CFU reduction remained low (1.0 log-unit) in the mutant, independent of adhesion force. This confirms that large channels open at a higher critical adhesion-force than small channels, as also concluded from calcein transmembrane transport. Collectively, these observations support our hypothesis that adhesion forces to surfaces play an important role, next to other established driving forces, in staphylococcal channel gating. This provides an interesting extension of our understanding of transmembrane antibiotic uptake and solute efflux in infectious staphylococcal biofilms in which bacteria experience adhesion forces from a wide variety of surfaces, like those of other bacteria, tissue cells, or implanted biomaterials.